TechPrufer
Get started
Cloudflare
Cloudflare logoCloudflare · Feature trail

Realtime

2 posts · Aug 2014 – May 2016

What this trail covers

Cloudflare's support for WebSockets has evolved from an initial offering for Enterprise customers to general availability for all plans, with resources allocated based on plan level. This expansion aims to enable a wider range of real-time applications, such as chat, games, and collaborative editing, by providing a persistent, bidirectional communication channel that significantly reduces latency and HTTP header overhead compared to polling solutions. The underlying infrastructure has been scaled to handle the unique connection profiles of WebSockets, including addressing challenges with ephemeral port exhaustion and connection tuple limitations through techniques like SO_REUSEADDR and expanded ephemeral port ranges.

All Cloudflare trails
  1. Everybody gets WebSocketsThis post announces the general availability of WebSocket support for all Cloudflare customers, expanding from an initial Enterprise-only offering. It highlights the performance benefits of WebSockets, including significant reductions in HTTP header traffic and latency compared to polling solutions. The post also contextualizes this advancement alongside HTTP/2 support, emphasizing Cloudflare's commitment to making modern web technologies accessible and driving innovation on its global network.
  2. CloudFlare Now Supports WebSocketsThis post announces Cloudflare's initial support for WebSockets, detailing the technical challenges and solutions involved. Key technical contributions include: - Explaining the limitations of traditional HTTP request/response models and the need for persistent, bidirectional connections like WebSockets. - Describing the challenges of WebSocket connection profiles, specifically longer-lived connections compared to HTTP. - Detailing the 'tuple' limitations (protocol, source IP, source port, destination IP, destination port) in managing connections to origin servers. - Explaining how Cloudflare addressed source IP limitations by spreading requests across multiple IPs. - Discussing the ephemeral port range and its limitations, and how Cloudflare expanded its range. - Detailing the 'bind before connect' issue in Linux and how it limited concurrent connections. - Introducing the solution of using SO_REUSEADDR to allow port reuse, enabling safe port reuse for managing a higher volume of long-lived WebSocket connections.